Surge recorder



Feb. 10, 1931. J, W, LEGG y 1,792,314

SURGE RECORDER Filed July 19, 1924 "WITNE 55's; :NVENTOR XMK Jose/B2b W/.gg

' AT'TORNEY Patented Feb. 10, 1931 UNITED STATES NPATENT OFFICE JOSEPH W. LEGG, F WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE f ELECTRIC 6c MANUFACTURING COMPANY, A CORPORATION 0F PENNSYLVANIA SURGE RECORDER Application filed July 19,

cal to manufacture and effective in its operation.

In copending application Serial No. 680,-

' 569, filed December 13, 1923, by J. F. Peters,

and assigned to the Westinghouse Electric & Mfg. Company, is set forth an instrument for recording steep wave front voltage surges, kaccording to the principles'of which my present invention operates and to which yreference may be had for a better understanding of my invention.

As disclosed in the copending application, variations in certain electrical quantities may readily be observed by the movement of a galvanometer element. However, there areV certain other electrical phenomena which oC- cur so quickly that the lightest known galvanometer element will not respond thereto.

As disclosed in the copending application, when an electrode engaging a grounded sensitized plate, such as a light-sensitive or photographic plate is subjected to certain highveltage surges, figures will be recorded on the plate from which the direction, magnitude and duration of the surge and the steepness of the wave front thereof may be determined.

The device of the copending application shows the electrode as stationary and the `Sensitized plate as rotatable relative thereto in order that the position of the surge figure upon the plate may provide an indication of the time that the surge occurred.

It is desirable in devices of this character, to employ standard photographic plates which are of rectangular shape. In order to utilize the maximum area of the plate foreffecting records, it is desirable in the first instance, to have the electrode and the plate move relatively so that a circle of maximum diameter may be described by the electrode over the surface of the plate. This object 1924. Serial No. 727,040.

may be accomplished more effectively and the space, occupied by the instrument as a unit, be reduced to substantially a minimum, considering the voltages employed and other factors of construction, by providing a stationary sensitized plate and having the electrode rotate relative thereto. Thus, the annular space that would be required in which to rotate the corners of the plate, were the plate rotatable, is conserved and the instruy ment rendered more compact.

Other features, such as a novel plate holder having means for maintaining a uniform space between the electrode and a ground plate or sheet beneath the sensitized plate and means for recording the surges in chronological order, assist in rendering the device of my invention compact in construction, easy to manipulate and effective in its operation.

Figure 1, of the accompanying drawings, isa view, partially in side elevation and partially in section, of a surge recorder constricted in accordance with my invention, an

Fig. 2 is a bottom view, taken along the line H II of Fig. l.

The device embodying my invention comprises, in general, a light-proof casing 1, a motive device or clockwork mechanism 2 disposed therein, a rotatable member or insulating disk 3 for actuation by the mechanism 2, an electrode 4 carried by the member 3, an annular contact member or slip ring 5, carried by the disk 3, a terminal member 7, a stationary contact member 8, mounted on the terminal member 7 for engagement with the annular contact member 5 and a plate holder 10.

The casing 1 preferably comprises a sheetmaterial. side-wall member 12, an insulating top-wall member 14, secured thereto, as by screws 15, and a bottom wall member 16 having an opening 17 therein. The opening 17 is preferably of circular shape and sufficiently larger' than the disk 3 to permit ready access thereto, when the plate holder 10 is not in position.

The clockwork mechanism 2, of a usual form, is provided for the purpose of driving the electrode 4 and is preferably suitably secured to the top wall member 14 of the casing 1 and provided with an arbor 19 having a iianged portion 2O and a stud portion 21. A disk 23 is rictionally held against the iiange 20 around the stud 21 by a spring'r Washery 24 or similar device'that is held in position by nuts 25 on thestud 21. The disk 3 is secured to the disk 23 by screws 27 and spaced therefrom by a ring or sleeve 28. v

The disk 3 is provided, on its under' surfac-e adjacent to the perimeter thereof, with scale-division marks 30 that correspond to divisions of the diurna-l period. A standard 31 depending from the top-wall member 14, carries an index orv pointer 32beneath the disk 3 for cooperation with the scale 30. The electrode 4 comprises aY conducting tube 34 that is preferably bent inwardly at its ends and iiXed to the disk 3 to .rotate iherewitlil A recording element or pin 35 has .portions of different diameters to provide Ya shoulder 36, in the tube 34, that limits movement of the element 35 in one direction, relative to the longitudinal axis of the tube 34. An adjustable nut37 on the element 35 limits movement of the latter in the opposite direction. is loosely mounted in the tube 34 in substantialiicating relation thereto, to move in one direction or the other along the axis ot the tube 34 in response to gravity. y

The plate liolder'lO comprises abase plate or member 40 and a rectangular trame member 41 having an inwardly projecting perimetral flange 42 under which a sensitized plate 44isadaptedto be received. A usual opaque plate (not shown) is provided to protect the plate 44 whenthe holder l0 is notV in operative position, A sheet 46 of flexible conducting material lies flat ragainst the underside of the rplate 44 and is adapted to be uniformly pressed, throughout its surface area, againstthe plate 44 Vby a pad 47y of yieldable material, such as'felt, The .conducting sheet 46 is secured to the base plate 40, as by a screw 48, and suitably connected to ground. The grounded plate 46 is preterably of circular shape having its outer perimeter extending beyond the path of travel of the electrode 4.

f The plate holder l() is received into the casing 1 through an opening 50, in one side wall member of the casing, over which a flexible element or ilap 51 is'secured, as by screws 52, vas protection against the admission of light to the casing.

The sensitized plate 44 is initially provided, as by the use of a suitable templet, with chronological markings, similar to those ot the scale 30 on the disk 3. Y n i ln operation, the instrument is initially inverted to permit the recording element 35 to tall, by gravity, out of the path along which theplate holder 10 is to be received.

The element 35v 'ing 50 and the instrument as a whole, re- 'turned to its normal operative position, as

shown in Fig. 1. `This operation permits the recording elenient ,35 to tall by gravity against the upper sensitized surface oi' the Yplate 34 uponthe removal'ot the usual opaque slide. The operation is then begun kby connectingtlie flexible conducting sheet 46 to ground and connecting the terminal Y7 to a circuit. Under these conditions, when a voltagesurge occurs, it will be recorded on the y plate A44, as described in the above mentioned copending application, in a definite position corresponding to the time of occurrence ot the surge.

The terminal 7 is connected to the system in which the occurrence of a surge isto be detected, through a suitable electrostatic .transformer YorQpotentionneter which will, at

the normal circuitvoltage, establish anv elec-v trostatic stress across the plate between the recording electrode v35 and the pla-te 46 that willbe below the critical value at which the plate willV be-iniuenced, Upon lthe occurrence of a surge, however, the. valuefot such Stress will be amplified to a value excess of the critical value of the plate, and a record will be made upon the plate indicative of the character and intensity of the surge.

The plateconstitutes a dielectric betweenv the recording electrode 35, which is at high potential, when energized, and the ground plate 4,6, vwhich is at ground potential." Y l/Vhile I have shown and described a partcular form of my invention, various iiijoli` icatons and changes be made therein without departing from the spirit and scope thereof and l desire that only such limitations shall be placed thereon as are imposed by the prior art orare set forth in the appended claims. i

' I claim as my invention:

1. A surge recorder including an insulating disk, means for rotating the disk, a spacedischarge electrode structure supported by the ydisk transversely to the plane thereof, an annular contact element supported by vthe disk and connected to said electrode, and va stationary Contact element cooperatingwith said annular contact element. Y o

2. A ,surge recorder including an insulating disk, meansior rotating the disk, a tubular body extending transversely through the disk adjacent to, but slightly displaced from,

the 'outer perimeter thereofg a .Space-discharge electrode movable longitudinally in said body, an annular contact element supported on the perimeter of the disk and connected to said electrode, and a stationary contact element cooperating With said annular contact element.

3. An instrument for electrostatically recording ythe characteristics of surges occurring on an electric circuit comprising an electrically grounded stationary element, a sensitized record chart supported thereon, an electrode-supporting means rotatably supported above said chart for rotation in a plane parallel to the plane of said chart, an electrode carried by said means and adapted to engage the face of said chart, and chronological markings on said record chart and supporting means to permit a desired registration of said electrode with said chart.y

4. In a surge recorder, the combination with a sensitized record chart, of an electrode relatively movable with respect thereto and operative to record successive steep-Wavefront voltage surges on one side of said record chart, means for connecting said electrode to an external circuit, a supporting base member for said chart, a flexible grounded element engaging the other side of the chart and yieldable means between the base mem1 ber and the grounded element for uniformly f ressinfr the same afrainst the chart.

In testimony whereof, I have hereunto subscribed my name this 26th day of June,

JOSEPH W. LEGG. 

